Unmanned forklift carrying method and system based on synchronous motor

Abstract

An unmanned forklift carrying method based on a synchronous motor comprises the following steps that a current conveying line is obtained, road segment segmentation is conducted according to a turning point, an initial point and a destination point in the conveying line, and a plurality of road segments are obtained; the weight of goods loaded by the unmanned forklift is obtained, and the final braking distance is determined according to the weight of the goods; acquiring operation parameters of a synchronous motor of the unmanned forklift, and determining an acceleration distance according to the operation parameters; road sections are divided according to the final braking distance and / or the acceleration distance, a control section in each road section is determined, and the control section comprises a deceleration section, an acceleration section and a constant speed section; according to the method, the acceleration distance can be calculated, then the road section is divided according to the final braking distance and / or the acceleration distance, and the section in the road section needs to be accelerated and the section in the road section needs to be decelerated are determined, so that the running speed of the unmanned forklift in different control sections in the road section is planned; and the transportation efficiency can be ensured while stable transportation is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of unmanned forklift control, and in particular to an unmanned forklift handling method and system based on a synchronous motor. Background Art

[0002] In the automated production workshop, in order to solve the problem of cargo transportation, an unmanned forklift is designed for automatic transportation. Before the cargo is transported, the transportation route of the unmanned forklift needs to be set in advance. After the workers load the cargo, they can start the unmanned forklift, which will transport the cargo to the corresponding destination according to the pre-set transportation route.

[0003] However, during transportation, the goods are usually not limited or tied, which makes the goods vulnerable to inertia during movement, especially at the turning position of the conveying route, where the goods are prone to falling. Therefore, how to effectively control the unmanned forklift to prevent the goods from falling when turning has become an urgent problem to be solved. Summary of the invention

[0004] In view of the above-mentioned defects, the purpose of the present invention is to propose an unmanned forklift handling method and system based on a synchronous motor to solve the problem of cargo falling due to poor stability of the unmanned forklift when turning.

[0005] To achieve this purpose, the present invention adopts the following technical solution: an unmanned forklift handling method based on a synchronous motor, comprising the following steps:

[0006] Step S1: obtaining the current transmission route, dividing the route into sections according to the turning points, the initial points and the destination points in the transmission route, and obtaining multiple sections;

[0007] Step S2: Obtain the weight of the cargo loaded by the unmanned forklift, and determine the final braking distance according to the weight of the cargo;

[0008] Step S3: obtaining the operating parameters of the synchronous motor of the unmanned forklift, and determining the acceleration distance according to the operating parameters;

[0009] Step S4: Divide the road section according to the final braking distance and / or acceleration distance, and determine a control section in each road section, wherein the control section includes a deceleration section, an acceleration section, and a constant speed section;

[0010] Step S5: When the unmanned forklift passes through different control sections, the speed of the unmanned forklift is controlled accordingly.

[0011] Preferably, the steps of obtaining the final braking distance in step S2 are as follows:

[0012] Step S21: selecting a speed range for the unmanned forklift according to the weight of the cargo;

[0013] Step S22: obtaining the highest speed in the speed range as the first computing speed, obtaining the friction coefficient of the tire of the unmanned forklift, and obtaining the preliminary braking distance through the friction coefficient and the first computing speed;

[0014] Step S23: obtaining the weight of the unmanned forklift and the cargo as the total weight, and obtaining the inertia adjustment coefficient according to the total weight, the friction coefficient and the first computing speed;

[0015] Step S24: The final braking distance is obtained by multiplying the inertia adjustment coefficient by the preliminary braking distance.

[0016] Preferably, the specific formula for obtaining the preliminary braking distance in step S22 is as follows:

[0017]

[0018] Where S1 is the initial braking distance, V1 is the first operating speed, g is the acceleration of gravity, and μ is the friction coefficient;

[0019] The specific formula for obtaining the inertia adjustment coefficient in step S23 is as follows:

[0020]

[0021] Where C is an error correction coefficient greater than 1, a1, a2, a3 are the total weight adjustment factor, speed adjustment factor and friction coefficient adjustment factor respectively, and m is the total weight.

[0022] Preferably, the step of determining the acceleration distance in step S3 is as follows:

[0023] Step S31: obtaining the lowest speed in the speed interval as the second operation speed;

[0024] Get the maximum torque of the motor;

[0025] Step S32: obtaining the acceleration of the unmanned forklift by using the total mass and the maximum torque;

[0026] Step S33: obtaining the acceleration distance through the acceleration and the second computing speed;

[0027] The formula for obtaining the acceleration is as follows:

[0028]

[0029] The formula for obtaining the acceleration distance is as follows:

[0030]

[0031] Wherein F is the maximum torque, and V2 is the second operating speed.

[0032] Preferably, the rules for determining the deceleration segment, the acceleration segment and the uniform speed segment in step S4 are as follows:

[0033] The sum of the final braking distance and the acceleration distance is obtained as the first distance;

[0034] If the length of the road section is greater than the first distance, the starting point of the road section is taken as the first base point, and the first base point plus the acceleration distance along the direction of the end point is taken as the acceleration section of the road section. The end point of the road section is taken as the second base point, and the second base point plus the final braking distance along the direction of the starting point is taken as the deceleration section of the road section. The remaining road section is taken as the uniform speed section.

[0035] If the road section length is greater than the final braking distance and the road section length is less than the first distance, the difference between the road section length and the final braking distance is obtained as the length difference;

[0036] Get the ratio between the length difference and the acceleration distance. If the ratio is greater than 80%, the end point of the road section is used as the second base point. The second base point plus the final braking distance along the starting point direction is used as the deceleration section of the road section. The remaining section is used as the acceleration section, and no uniform speed section is set.

[0037] If the ratio is greater than 30% and less than 80%, the first computing speed is replaced by the second computing speed, the final braking distance is updated, and the sum of the updated final braking distance and the acceleration distance is obtained as the second distance;

[0038] Determine whether the second distance is less than the length of the road section. If so, take the starting point of the road section as the first base point, add the acceleration distance from the first base point along the direction of the end point as the acceleration section of the road section, take the end point of the road section as the second base point, add the final braking distance from the second base point along the direction of the starting point as the deceleration section of the road section, and the remaining road section as the uniform speed section;

[0039] If it is greater than, the end point of the road section is taken as the second base point, and the second base point plus the final braking distance along the starting point direction is taken as the deceleration section of the road section, and the remaining section is taken as the acceleration section, and no uniform speed section is set;

[0040] If the ratio is less than 30%, the road section is set as a uniform speed section or a deceleration section;

[0041] If the length of the road section is less than the final braking distance, the road section is set as a constant speed section or a deceleration section.

[0042] Preferably, in step S5, the rules for controlling the speed of the unmanned forklift are as follows:

[0043] When the unmanned forklift enters the acceleration section, the unmanned forklift is controlled to accelerate until the speed of the unmanned forklift reaches the second operation speed;

[0044] When the unmanned forklift enters the uniform speed section, the unmanned forklift is controlled to maintain the speed of the previous control section;

[0045] When the unmanned forklift enters the deceleration section, the unmanned forklift is controlled to decelerate until the speed of the unmanned forklift reaches the preset speed.

[0046] An unmanned forklift handling system based on a synchronous motor, using the unmanned forklift handling method based on a synchronous motor, comprising: a segmentation module, a first distance acquisition module, a second distance acquisition module, a control segment determination module and a speed control module;

[0047] The segmentation module is used to obtain the current transmission route, and segment the route according to the turning point, the initial point and the destination point in the transmission route to obtain multiple sections;

[0048] The first distance acquisition module is used to obtain the weight of the cargo loaded by the unmanned forklift and determine the final braking distance according to the weight of the cargo;

[0049] The second distance acquisition module is used to obtain the operating parameters of the synchronous motor of the unmanned forklift and determine the acceleration distance according to the operating parameters;

[0050] The control segment determination module is used to divide the road segment according to the final braking distance and / or acceleration distance, and determine the control segment in each road segment, wherein the control segment includes a deceleration segment, an acceleration segment and a constant speed segment;

[0051] The speed control module is used to control the speed of the unmanned forklift accordingly when the unmanned forklift passes through different control sections.

[0052] Preferably, the first distance acquisition module includes an interval submodule, a preliminary distance submodule, an inertia coefficient submodule and an adjustment module;

[0053] The interval submodule is used to select the speed interval of the unmanned forklift according to the weight of the cargo;

[0054] The preliminary distance submodule is used to obtain the highest speed in the speed range as the first computing speed, obtain the friction coefficient of the tire of the unmanned forklift, and obtain the preliminary braking distance through the friction coefficient and the first computing speed;

[0055] The inertia coefficient submodule is used to obtain the weight of the unmanned forklift and the cargo as the total weight, and obtain the inertia adjustment coefficient according to the total weight, the friction coefficient and the first computing speed;

[0056] The adjustment module is used for obtaining the final braking distance by multiplying the inertia adjustment coefficient by the preliminary braking distance.

[0057] Preferably, the second distance acquisition module includes a selection submodule, an acceleration submodule and a calculation submodule;

[0058] The selection submodule is used to obtain the lowest speed in the speed range as the second operation speed;

[0059] Get the maximum torque of the motor;

[0060] The acceleration submodule is used to obtain the acceleration of the unmanned forklift through the total mass and the maximum torque;

[0061] The calculation submodule is used to obtain the acceleration distance through the acceleration and the second operation speed. One of the above technical solutions has the following advantages or beneficial effects: the present invention also calculates the acceleration distance, and then divides the road section by the final braking distance and / or the acceleration distance, and determines which section of the road section needs to be accelerated and which section needs to be decelerated, so as to plan the operating speed of the unmanned forklift in different control sections of the road section, ensuring stable transportation while also ensuring the efficiency of transportation. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 It is a flowchart schematic diagram of an embodiment of the method of the present invention.

[0063] Figure 2 It is a schematic diagram of the structure of an embodiment of the system of the present invention.

[0064] Figure 3 It is a diagram of the arrangement of a transport route in one embodiment of the present invention. DETAILED DESCRIPTION

[0065] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions from beginning to end. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0066] In the description of the embodiments of the present invention, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0067] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0068] like Figures 1 to 3 As shown, an unmanned forklift handling method based on a synchronous motor includes the following steps:

[0069] Step S1: obtaining the current transmission route, dividing the route into sections according to the turning points, the initial points and the destination points in the transmission route, and obtaining multiple sections;

[0070] Step S2: Obtain the weight of the cargo loaded by the unmanned forklift, and determine the final braking distance according to the weight of the cargo;

[0071] Step S3: obtaining the operating parameters of the synchronous motor of the unmanned forklift, and determining the acceleration distance according to the operating parameters;

[0072] Step S4: Divide the road section according to the final braking distance and / or acceleration distance, and determine a control section in each road section, wherein the control section includes a deceleration section, an acceleration section, and a constant speed section;

[0073] Step S5: When the unmanned forklift passes through different control sections, the speed of the unmanned forklift is controlled accordingly.

[0074] In order to prevent the unmanned forklift from throwing out the goods due to inertia when turning, the present invention is provided with a configuration that the transportation routes are divided preferentially, such as Figure 3As shown, point A and point F are the initial point and the destination point respectively, and points B, C, and D are turning points respectively. At this time, the adjacent points will be combined to obtain the corresponding road sections. For example, point A is combined with point B to obtain the first road section AB, and then point B and point C are combined to obtain the second road section BC. Similarly, sections CD, DE, and EF are obtained in sequence. Since the inertia of braking is different for goods of different weights after loading, it is necessary to obtain the weight of the goods loaded by the unmanned forklift, and determine the braking distance based on the weight of the goods, so as to ensure that the unmanned forklift can brake in advance, and when reaching the turning point to turn, the speed of the unmanned forklift will not cause the goods to be thrown out. In addition, since some sections of the road are long, if the goods are always transported at a lower speed, the transportation speed will be affected. For this reason, the acceleration distance is also calculated in the present invention, and then the section is divided according to the final braking distance and / or acceleration distance to determine which section of the section needs to be accelerated and which section needs to be decelerated, so as to plan the operating speed of the unmanned forklift in different control sections of the section, ensuring stable transportation while ensuring transportation efficiency.

[0075] Preferably, the steps of obtaining the final braking distance in step S2 are as follows:

[0076] Step S21: selecting a speed range for the unmanned forklift according to the weight of the cargo;

[0077] Step S22: obtaining the highest speed in the speed range as the first computing speed, obtaining the friction coefficient of the tire of the unmanned forklift, and obtaining the preliminary braking distance through the friction coefficient and the first computing speed;

[0078] Step S23: obtaining the weight of the unmanned forklift and the cargo as the total weight, and obtaining the inertia adjustment coefficient according to the total weight, the friction coefficient and the first computing speed;

[0079] Step S24: The final braking distance is obtained by multiplying the inertia adjustment coefficient by the preliminary braking distance.

[0080] Before obtaining the final braking distance, it is necessary to determine the safe speed of this type of unmanned forklift when transporting goods of different weights through multiple groups. Because of the influence of the environment, the speed will usually be a speed range. For example, when the goods are between 80 and 100 kg, they can be transported at a speed of 10 to 15 km / h. After the speed range is selected, the initial braking distance will be obtained at the highest speed in the range, because calculating at the highest speed can increase the length of the initial braking distance and ensure that the unmanned forklift has enough distance to slow down.

[0081] However, due to the influence of inertia, even if the initial braking distance is increased, the unmanned forklift will run faster when turning, causing the cargo to fall. Therefore, the present invention takes into account the influence of inertia and calculates the inertia adjustment coefficient to adjust the initial braking distance to ensure that there is enough length for the unmanned forklift to decelerate.

[0082] Preferably, the specific formula for obtaining the preliminary braking distance in step S22 is as follows:

[0083]

[0084] Where S1 is the initial braking distance, V1 is the first operating speed, g is the acceleration of gravity, and μ is the friction coefficient;

[0085] The specific formula for obtaining the inertia adjustment coefficient in step S23 is as follows:

[0086]

[0087] Where C is an error correction coefficient greater than 1, a1, a2, a3 are the total weight adjustment factor, speed adjustment factor and friction coefficient adjustment factor respectively, and m is the total weight.

[0088] Preferably, the step of determining the acceleration distance in step S3 is as follows:

[0089] Step S31: obtaining the lowest speed in the speed interval as the second operation speed;

[0090] Get the maximum torque of the motor;

[0091] Step S32: obtaining the acceleration of the unmanned forklift by using the total mass and the maximum torque;

[0092] Step S33: obtaining the acceleration distance through the acceleration and the second computing speed;

[0093] The formula for obtaining the acceleration is as follows:

[0094]

[0095] The formula for obtaining the acceleration distance is as follows:

[0096]

[0097] Wherein F is the maximum torque, and V2 is the second operating speed.

[0098] The second transport speed is the speed that the unmanned forklift finally accelerates to. When determining the acceleration distance, the lowest speed in the speed range will be used as the second computing speed. Because the actual environment is different from the test environment, the ground friction in the actual environment may be smaller than the ground friction in the test environment. If the first computing speed is used to calculate the first acceleration distance, the transportation speed of the unmanned forklift after acceleration will be greater than the first computing speed, resulting in insufficient distance for deceleration, affecting the stability of transportation. If the acceleration distance is calculated using the second computing speed, the speed of the unmanned forklift after final acceleration can be reduced. The unmanned forklift can reduce its speed in the deceleration section to a speed at which it can turn stably.

[0099] Preferably, the rules for determining the deceleration segment, the acceleration segment and the uniform speed segment in step S4 are as follows:

[0100] The sum of the final braking distance and the acceleration distance is obtained as the first distance;

[0101] If the length of the road section is greater than the first distance, the starting point of the road section is taken as the first base point, and the first base point plus the acceleration distance along the direction of the end point is taken as the acceleration section of the road section. The end point of the road section is taken as the second base point, and the second base point plus the final braking distance along the direction of the starting point is taken as the deceleration section of the road section. The remaining road section is taken as the uniform speed section.

[0102] If the road section length is greater than the final braking distance and the road section length is less than the first distance, the difference between the road section length and the final braking distance is obtained as the length difference;

[0103] Get the ratio between the length difference and the acceleration distance. If the ratio is greater than 80%, the end point of the road section is used as the second base point. The second base point plus the final braking distance along the starting point direction is used as the deceleration section of the road section. The remaining section is used as the acceleration section, and no uniform speed section is set.

[0104] If the ratio is greater than 30% and less than 80%, the first computing speed is replaced by the second computing speed, the final braking distance is updated, and the sum of the updated final braking distance and the acceleration distance is obtained as the second distance;

[0105] Determine whether the second distance is less than the length of the road section. If so, take the starting point of the road section as the first base point, add the acceleration distance from the first base point along the direction of the end point as the acceleration section of the road section, take the end point of the road section as the second base point, add the final braking distance from the second base point along the direction of the starting point as the deceleration section of the road section, and the remaining road section as the uniform speed section;

[0106] If it is greater than, the end point of the road section is taken as the second base point, and the second base point plus the final braking distance along the starting point direction is taken as the deceleration section of the road section, and the remaining section is taken as the acceleration section, and no uniform speed section is set;

[0107] If the ratio is less than 30%, the road section is set as a uniform speed section or a deceleration section;

[0108] If the length of the road section is less than the final braking distance, the road section is set as a constant speed section or a deceleration section.

[0109] like Figure 3 As shown, in section AB, point A in section AB will be the starting point of the section, and point B is the end point of the section. The length of section AB is greater than the first distance. At this time, point A will be used as the first base point, and the acceleration distance will be increased from the first base point to the direction of point B to obtain the acceleration section. At the same time, point B will be used as the second base point, and the final braking distance will be increased from the second base point to the direction of point A to obtain the deceleration section. At this time, the section between the acceleration section and the deceleration section is used as the uniform speed section.

[0110] When the length of the road section is greater than the final braking distance and the length of the road section is less than the first distance, it means that the unmanned forklift has not accelerated to the second operating speed and needs to decelerate. Therefore, when this happens, the difference between the road section length and the final braking distance will be obtained as the length difference; the ratio between the length difference and the acceleration distance is obtained. If the ratio is greater than 80%, it means that there is a certain distance for the unmanned forklift to accelerate and increase the transportation speed of the unmanned forklift. However, in order to ensure a smooth turn, the length of the deceleration section is maintained, and the remaining road section is used as an acceleration section for acceleration.

[0111] When the ratio is greater than 30% and less than 80%, the remaining road section will not reach the second operation speed even if it is accelerated, because the final braking distance at the beginning is calculated by the first operation speed, leaving a tolerance distance. When the acceleration cannot reach the second transportation speed, the tolerance distance is useless. For this reason, the present invention uses the second operation speed instead of the first operation speed to update the final braking distance. By shortening the length of the deceleration section, the length of the remaining road section is increased, and then the corresponding road section is divided. This improves the transportation efficiency of the unmanned forklift.

[0112] When the ratio is less than 30%, the acceleration effect of the unmanned forklift is minimal, and the unmanned forklift will not accelerate at this time, and the remaining road section will be set as a uniform speed section or a deceleration section. Similarly, when the road section length is less than the final braking distance, the acceleration effect of the unmanned forklift is minimal, and the road section will be set as a uniform speed section or a deceleration section.

[0113] Preferably, in step S5, the rules for controlling the speed of the unmanned forklift are as follows:

[0114] When the unmanned forklift enters the acceleration section, the unmanned forklift is controlled to accelerate until the speed of the unmanned forklift reaches the second operation speed;

[0115] When the unmanned forklift enters the uniform speed section, the unmanned forklift is controlled to maintain the speed of the previous control section;

[0116] When the unmanned forklift enters the deceleration section, the unmanned forklift is controlled to decelerate until the speed of the unmanned forklift reaches the preset speed.

[0117] The preset speed is the speed at which the unmanned forklift can stably turn. The speed is a preset value, generally set to 5 to 7 km / h, and can be selected according to different weights.

[0118] The uniform speed section is based on the speed of the previous control end as the speed maintained by the uniform speed section. If the previous section is an acceleration section, the speed reached by the acceleration section is used as the speed maintained by the uniform speed section. If the previous section is a deceleration section, the preset speed is used as the speed maintained by the uniform speed section.

[0119] An unmanned forklift handling system based on a synchronous motor, using the unmanned forklift handling method based on a synchronous motor, comprising: a segmentation module, a first distance acquisition module, a second distance acquisition module, a control segment determination module and a speed control module;

[0120] The segmentation module is used to obtain the current transmission route, and segment the route according to the turning point, the initial point and the destination point in the transmission route to obtain multiple sections;

[0121] The first distance acquisition module is used to obtain the weight of the cargo loaded by the unmanned forklift and determine the final braking distance according to the weight of the cargo;

[0122] The second distance acquisition module is used to obtain the operating parameters of the synchronous motor of the unmanned forklift and determine the acceleration distance according to the operating parameters;

[0123] The control segment determination module is used to divide the road segment according to the final braking distance and / or acceleration distance, and determine the control segment in each road segment, wherein the control segment includes a deceleration segment, an acceleration segment and a constant speed segment;

[0124] The speed control module is used to control the speed of the unmanned forklift accordingly when the unmanned forklift passes through different control sections.

[0125] Preferably, the first distance acquisition module includes an interval submodule, a preliminary distance submodule, an inertia coefficient submodule and an adjustment module;

[0126] The interval submodule is used to select the speed interval of the unmanned forklift according to the weight of the cargo;

[0127] The preliminary distance submodule is used to obtain the highest speed in the speed range as the first computing speed, obtain the friction coefficient of the tire of the unmanned forklift, and obtain the preliminary braking distance through the friction coefficient and the first computing speed;

[0128] The inertia coefficient submodule is used to obtain the weight of the unmanned forklift and the cargo as the total weight, and obtain the inertia adjustment coefficient according to the total weight, the friction coefficient and the first computing speed;

[0129] The adjustment module is used for obtaining the final braking distance by multiplying the inertia adjustment coefficient by the preliminary braking distance.

[0130] Preferably, the second distance acquisition module includes a selection submodule, an acceleration submodule and a calculation submodule;

[0131] The selection submodule is used to obtain the lowest speed in the speed range as the second operation speed;

[0132] Get the maximum torque of the motor;

[0133] The acceleration submodule is used to obtain the acceleration of the unmanned forklift through the total mass and the maximum torque;

[0134] The calculation submodule is used to obtain the acceleration distance through acceleration and a second operating speed. In the description of this specification, the description of reference terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0135] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. An unmanned forklift handling method based on a synchronous motor, characterized in that: The steps include: Step S1: obtaining the current transmission route, dividing the route into sections according to the turning points, the initial points and the destination points in the transmission route, and obtaining multiple sections; Step S2: Obtain the weight of the cargo loaded by the unmanned forklift, and determine the final braking distance according to the weight of the cargo; Step S3: obtaining the operating parameters of the synchronous motor of the unmanned forklift, and determining the acceleration distance according to the operating parameters; Step S4: Divide the road section according to the final braking distance and / or acceleration distance, and determine a control section in each road section, wherein the control section includes a deceleration section, an acceleration section, and a constant speed section; Step S5: When the unmanned forklift passes through different control sections, the speed of the unmanned forklift is controlled accordingly.

2. The unmanned forklift handling method based on a synchronous motor according to claim 1 is characterized in that: The steps for obtaining the final braking distance in step S2 are as follows: Step S21: selecting a speed range for the unmanned forklift according to the weight of the cargo; Step S22: obtaining the highest speed in the speed range as the first computing speed, obtaining the friction coefficient of the tire of the unmanned forklift, and obtaining the preliminary braking distance through the friction coefficient and the first computing speed; Step S23: obtaining the weight of the unmanned forklift and the cargo as the total weight, and obtaining the inertia adjustment coefficient according to the total weight, the friction coefficient and the first computing speed; Step S24: The final braking distance is obtained by multiplying the inertia adjustment coefficient by the preliminary braking distance.

3. The unmanned forklift handling method based on a synchronous motor according to claim 2, characterized in that: The specific formula for obtaining the preliminary braking distance in step S22 is as follows: Where S1 is the initial braking distance, V1 is the first operating speed, g is the acceleration of gravity, and μ is the friction coefficient; The specific formula for obtaining the inertia adjustment coefficient in step S23 is as follows: Where C is an error correction coefficient greater than 1, a1, a2, a3 are the total weight adjustment factor, speed adjustment factor and friction coefficient adjustment factor respectively, and m is the total weight.

4. The unmanned forklift handling method based on a synchronous motor according to claim 2 is characterized in that: The steps for determining the acceleration distance in step S3 are as follows: Step S31: obtaining the lowest speed in the speed interval as the second operation speed; Get the maximum torque of the motor; Step S32: obtaining the acceleration of the unmanned forklift by using the total mass and the maximum torque; Step S33: obtaining the acceleration distance through the acceleration and the second computing speed; The formula for obtaining the acceleration is as follows: The formula for obtaining the acceleration distance is as follows: Wherein F is the maximum torque, and V2 is the second operating speed.

5. The unmanned forklift handling method based on a synchronous motor according to claim 1, characterized in that: The rules for determining the deceleration segment, acceleration segment and uniform speed segment in step S4 are as follows: The sum of the final braking distance and the acceleration distance is obtained as the first distance; If the length of the road section is greater than the first distance, the starting point of the road section is taken as the first base point, and the first base point plus the acceleration distance along the direction of the end point is taken as the acceleration section of the road section. The end point of the road section is taken as the second base point, and the second base point plus the final braking distance along the direction of the starting point is taken as the deceleration section of the road section. The remaining road section is taken as the uniform speed section. If the road section length is greater than the final braking distance and the road section length is less than the first distance, the difference between the road section length and the final braking distance is obtained as the length difference; Get the ratio between the length difference and the acceleration distance. If the ratio is greater than 80%, the end point of the road section is used as the second base point. The second base point plus the final braking distance along the starting point direction is used as the deceleration section of the road section. The remaining section is used as the acceleration section, and no uniform speed section is set. If the ratio is greater than 30% and less than 80%, the first computing speed is replaced by the second computing speed, the final braking distance is updated, and the sum of the updated final braking distance and the acceleration distance is obtained as the second distance; Determine whether the second distance is less than the length of the road section. If so, take the starting point of the road section as the first base point, add the acceleration distance from the first base point along the direction of the end point as the acceleration section of the road section, take the end point of the road section as the second base point, add the final braking distance from the second base point along the direction of the starting point as the deceleration section of the road section, and the remaining road section as the uniform speed section; If it is greater than, the end point of the road section is taken as the second base point, and the second base point plus the final braking distance along the starting point direction is taken as the deceleration section of the road section, and the remaining section is taken as the acceleration section, and no uniform speed section is set; If the ratio is less than 30%, the road section is set as a uniform speed section or a deceleration section; If the length of the road section is less than the final braking distance, the road section is set as a constant speed section or a deceleration section.

6. The unmanned forklift handling method based on a synchronous motor according to claim 1, characterized in that: In step S5, the rules for controlling the speed of the unmanned forklift are as follows: When the unmanned forklift enters the acceleration section, the unmanned forklift is controlled to accelerate until the speed of the unmanned forklift reaches the second operation speed; When the unmanned forklift enters the uniform speed section, the unmanned forklift is controlled to maintain the speed of the previous control section; When the unmanned forklift enters the deceleration section, the unmanned forklift is controlled to decelerate until the speed of the unmanned forklift reaches the preset speed.

7. An unmanned forklift handling system based on a synchronous motor, using an unmanned forklift handling method based on a synchronous motor according to any one of claims 1 to 6, characterized in that: include: A segmentation module, a first distance acquisition module, a second distance acquisition module, a control segment determination module, and a speed control module; The segmentation module is used to obtain the current transmission route, and segment the route according to the turning point, the initial point and the destination point in the transmission route to obtain multiple sections; The first distance acquisition module is used to obtain the weight of the cargo loaded by the unmanned forklift and determine the final braking distance according to the weight of the cargo; The second distance acquisition module is used to obtain the operating parameters of the synchronous motor of the unmanned forklift and determine the acceleration distance according to the operating parameters; The control segment determination module is used to divide the road segment according to the final braking distance and / or acceleration distance, and determine the control segment in each road segment, wherein the control segment includes a deceleration segment, an acceleration segment and a constant speed segment; The speed control module is used to control the speed of the unmanned forklift accordingly when the unmanned forklift passes through different control sections.

8. The unmanned forklift handling system based on a synchronous motor according to claim 7 is characterized in that: The first distance acquisition module includes an interval submodule, a preliminary distance submodule, an inertia coefficient submodule and an adjustment module; The interval submodule is used to select the speed interval of the unmanned forklift according to the weight of the cargo; The preliminary distance submodule is used to obtain the highest speed in the speed range as the first computing speed, obtain the friction coefficient of the tire of the unmanned forklift, and obtain the preliminary braking distance through the friction coefficient and the first computing speed; The inertia coefficient submodule is used to obtain the weight of the unmanned forklift and the cargo as the total weight, and obtain the inertia adjustment coefficient according to the total weight, the friction coefficient and the first computing speed; The adjustment module is used for obtaining the final braking distance by multiplying the inertia adjustment coefficient by the preliminary braking distance.

9. The unmanned forklift handling system based on a synchronous motor according to claim 7, characterized in that: The second distance acquisition module includes a selection submodule, an acceleration submodule and a calculation submodule; The selection submodule is used to obtain the lowest speed in the speed range as the second operation speed; Get the maximum torque of the motor; The acceleration submodule is used to obtain the acceleration of the unmanned forklift through the total mass and the maximum torque; The calculation submodule is used to obtain the acceleration distance through the acceleration and the second operation speed.

Images